The general research goal is the elucidation of the structure, mechanism of action and role in the cell phosphoryl transferring enzymes. A molecular model of porcine adenylate kinase derived from X-ray diffraction at 3A resolution is available (Schulz, Elzinga, Marx and Schirmer, Nature (1974), 250, 120). This model serves as the starting point for the pursuit of understanding of how the enzyme works. Chemical modifications of porcine muscle adenylate kinase followed by kinetic and physical studies are being continued. Isolation of a related enzyme GTP-AMP phosphotransferase from beef heart mitochondrial matrix is being undertaken. BIBLIOGRAPHIC REFERENCES: Yazawa, M. and Noda, L. Studies on Tyrosine Residues in Porcine Muscle Adenylate Kinase; Circular Dichroism Spectra and Chemical Modification with Tetranitromethane. J. Biol. Chem. (1976) 251, 3021-3026. Abs.: Noda, L. and Schirmer, R.H. GTP-AMP Phosphotransferase from Beef Heart Mitochondria. Fed. Proc. (1977) 36.